Me and two friends saw an alien ship that looked like the ones on Star Wars.

I was walking home from school with my two friends. We decided to take a hike in the woods. We went about a mile out, and a aerodynamic ship flew across the sky. It sort of looked like the star destroyers on star wars, but smaller, about 500 metres. It was made of chrome, and quickly flew across the sky. None of us had cameras, and we don't know if anyone else saw it. It made a vibating noise, like a quiet car engine.